Cub stalls if I increase the throttle

Sun Feb 03, 2013 10:58 pm

My 49 starts fine at with throttle at about 1/3. If I increase the throttle, it stalls. However,even if I don't increase the throttle, there seems to be a narrow range in the choke adjustment to keep it running. Once it is going, it runs with the choke half open, but tends to shut off if I open or close the choke. I suspected a fuel flow issue, but when I detach the line from the carb, it flows well. Guessing the problem is in the carb, but I am looking for thoughts on this before I waste time in the wrong place.

Re: Cub stalls if I increase the throttle

Sun Feb 03, 2013 11:09 pm

This is one symptom of carburetor main jet issues, remove the hex head on the side of your carburetor (assuming you have an IH 3/4" updraft carburetor), clean out the orifice with a very small copper wire (telephone core works well), blow out with compressed air and reinstall, good luck.

Re: Cub stalls if I increase the throttle

Re: Cub stalls if I increase the throttle

Wed Feb 06, 2013 5:26 am

Then 1 trip across the yard you can do it over, and over! LOL!!--- the only way I could ever solve this problem, was to get rid of steel gas line from tank and go with super good grade of neoprene hose and a good grade of filter between tank and carb!---Wont fly with CP, but for yard use it works fine!---these little carbs will plug with a hair in the main jet,---they are micro holes! thanks; sonny

Re: Cub stalls if I increase the throttle

Wed Feb 06, 2013 9:32 am

I did put a piece of monofilament fishing line through the jet last week. I will try blowing air through it. Probably change the line, too. I think my tank might be the source of crud, but the sediment bowl filter should take care of that, shouldn't it?

Re: Cub stalls if I increase the throttle

Wed Feb 06, 2013 9:35 am

Probably the main jet like Brian suggested, but also make sure the small screen isn't plugged located inside the carb inlet(you can see it once the fuel line is moved) see this TM link=http://www.tmtractor.com/new/fl/195fp.htm

Rick

Re: Cub stalls if I increase the throttle

Wed Feb 06, 2013 11:05 am

When you take the jet out you should have a good stream of gas coming out the carb.

Re: Cub stalls if I increase the throttle

Wed Feb 06, 2013 1:04 pm

Sonny, most folks recommend the original steel fuel line. Why do you say that the neoprene line is a better choice? Thanks, Stanley

Re: Cub stalls if I increase the throttle

Wed Feb 06, 2013 1:41 pm

thiggy wrote:Sonny, most folks recommend the original steel fuel line. Why do you say that the neoprene line is a better choice? Thanks, Stanley

He is putting an inline filter in it. If you have a dirty Tank and can not get it clean. An in line filter made for gravity flow is the way to go. Thus the rubber line. And you can put a shut off valve in it too

Re: Cub stalls if I increase the throttle

Wed Feb 06, 2013 2:24 pm

Another option for supplemental fuel filtering from the "How To" forum. This method greatly diminishes detection by the CP if so desired.... viewtopic.php?f=139&t=74909